Heater product, system and composition

ABSTRACT

A heater product may have a first cavity in which a first part of a heater composition is disposed, a second cavity in which a second part of a heater composition is disposed, and a barrier between the first cavity and the second cavity, such that when the barrier is removed, the first and second parts combine to provide an exothermic reaction. A pull strip may be used to remove the barrier, and at least one reinforcing strip may be used to guide the pull strip. The first part may include calcium oxide and the second part may include water, an reaction-initiation delayer and water-release limiter.

This application claims the benefit of U.S. Provisional Application Ser.Nos. 60/567,878, 60/641,975, and 60/642,652, which were filed May 4,2004, Jan. 7, 2005, and Jan. 10, 2005, respectively, and which arehereby incorporated by reference in their entirety in the presentapplication.

TECHNICAL FIELD

The present disclosure is directed to a heater product, system andcomposition, and in particular to a flameless heater product, system andcomposition.

SUMMARY OF THE INVENTION

According to one aspect of the present disclosure, a heater product isprovided. The heater product has a first cavity in which a first part ofa heater composition is disposed, the first part comprising calciumoxide, a second cavity in which a second part of a heater composition isdisposed, the second part including water, an reaction-initiationdelayer and water-release limiter, and a barrier between the firstcavity and the second cavity, such that when the barrier is removed, thefirst and second parts combine to provide an exothermic reaction.

According to another aspect of the present disclosure, another heaterproduct is provided. The heater product includes an outer pouch, theouter pouch having a wall with an inner surface that defines an outerpouch cavity and an opening therethrough, an inner pouch disposed withinthe outer pouch cavity and attached to the outer pouch, the inner pouchhaving a wall with an inner surface that defines at least one innerpouch cavity and an outer surface, and a pull strip with a first portionsecured to the outer surface of the inner pouch and a second portiondisposed through the opening in the outer pouch. At least onereinforcing strip is secured to the outer surface of the inner pouch toguide a tear formed in the wall of the inner pouch when force is appliedto the pull strip. A first part of a heater composition is disposed inthe outer pouch cavity and a second part of a heater composition isdisposed in the inner pouch cavity, the first and second parts capableof an exothermic reaction when combined.

Additional aspects of the disclosure are defined by the claims of thispatent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a heater product according to thepresent disclosure;

FIG. 2 is a perspective view, partially in section, of the heaterproduct of FIG. 1;

FIG. 3 is an enlarged, perspective view of a sealing mechanism for thereleasing mechanism of the heater product of FIG. 1;

FIG. 4 is a sectional view of a first embodiment of a heater system,including the heater product of FIGS. 1-3;

FIG. 4A is a perspective view of the embodiment of the heater system ofFIG. 4, as assembled, ready to ship;

FIG. 5 is a perspective view of a second embodiment of a heater system,with the heater product removed;

FIG. 6 is a sectional view of the heater system of FIG. 5, with theheater product included;

FIG. 7 is a perspective view of a third embodiment of a heater systemsimilar to that shown in FIG. 5;

FIG. 8 is a frontal view of the heater system of FIG. 7;

FIG. 9 is a side elevational view of the heater system of FIG. 7;

FIG. 10 is a plan view of the heater system of FIG. 7;

FIG. 11 is a perspective view of a fourth embodiment of a heater system,with the heater product removed;

FIG. 12 is a sectional view of the heater system of FIG. 11, with theheater product included;

FIG. 13 is an exploded, perspective view of a fifth embodiment of aheater system, with the heater product removed;

FIG. 14 is a sectional view of the heater system of FIG. 13, with theheater product included;

FIG. 15 is a sectional view of another embodiment of a heater product;

FIG. 16 is a plan view of another embodiment of an inner pouch, with thepull tab removed;

FIG. 17 is a plan view of the inner pouch of FIG. 16, with the pull tabshown;

FIG. 18 is a perspective view of another embodiment of a heater product;

FIG. 19 is a perspective view, partially in section, of the heaterproduct of FIG. 18;

FIG. 20A is an exploded view of a sealing mechanism for use with theheater product of FIG. 18;

FIG. 20B is a perspective view of the sealing mechanism of FIG. 20A, asassembled;

FIG. 20C is a perspective view of the heater product, in fragmentarysection, of the heater product of FIG. 18 and the sealing mechanism ofFIG. 20A, as assembled;

FIG. 21 is a plan view, in section, of the inner pouch of the heaterproduct of FIG. 18;

FIG. 22 is a plan view of the inner pouch of the heater product of FIG.18; and

FIG. 23 is a bottom view of the inner pouch of the heater product ofFIG. 18.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Although the following text sets forth a detailed description ofnumerous different embodiments of the invention, it should be understoodthat the legal scope of the invention is defined by the words of theclaims set forth at the end of this patent. The detailed description isto be construed as exemplary only and does not describe every possibleembodiment of the invention since describing every possible embodimentwould be impractical, if not impossible. Numerous alternativeembodiments could be implemented, using either current technology ortechnology developed after the filing date of this patent, which wouldstill fall within the scope of the claims defining the invention.

It should also be understood that, unless a term is expressly defined inthis patent using the sentence “As used herein, the term ‘______’ ishereby defined to mean . . . ” or a similar sentence, there is no intentto limit the meaning of that term, either expressly or by implication,beyond its plain or ordinary meaning, and such term should not beinterpreted to be limited in scope based on any statement made in anysection of this patent (other than the language of the claims). To theextent that any term recited in the claims at the end of this patent isreferred to in this patent in a manner consistent with a single meaning,that is done for sake of clarity only so as to not confuse the reader,and it is not intended that such claim term be limited, by implicationor otherwise, to that single meaning. Finally, unless a claim element isdefined by reciting the word “means” and a function without the recitalof any structure, it is not intended that the scope of any claim elementbe interpreted based on the application of 35 U.S.C. §112, sixthparagraph.

FIG. 1 illustrates a heater product 20 for use in a heater system 22,five embodiments of which are shown in FIGS. 4-14.

As shown in FIG. 1, the heater product 20 may include an outer pouch 24having a first end 26 and a second end 28. The outer pouch 24 mayinclude a pouch wall 30, which may be flexible, semi-rigid, rigid, etc.,having an outer surface 32 and an inner surface 34, as shown in FIGS. 3and 4. The inner surface 34 of the pouch wall 30 may define a cavity 36in which is disposed an inner pouch 38. The inner surface 34 of thepouch wall 30 may be described as having a first section 40 and a secondsection 42, which with the pouch 24 disposed as illustrated in FIGS. 2and 4 may be described as an upper section 40 and a lower section 42.

The inner pouch 38 also has a first end 44 and a second end 46. As shownin FIGS. 2 and 4, the inner pouch 38 also includes a pouch wall 48having an outer surface 50 and an inner surface 52. Moreover, the innersurface 52 of the pouch wall 48 may be described as having a first (orupper) section 54 and a second (or lower) section 56, with the innerpouch 38 disposed in the orientation illustrated in FIGS. 2 and 4.

It should be noted that designations such as “upper” and “lower” are forease of discussion only, and are not meant to limit the disclosure inany fashion, for a similar designation may be used if the pouch wasinverted with the section 42 being “upper” and the section 40 being“lower” and the section 56 being “upper” and the section 54 being“lower.”

As illustrated in FIG. 2, the wall 48 of the inner pouch 38 may besealed at both the first and second ends 44, 46. As seen in FIG. 4, theupper and lower sections 54, 56 of the inner surface 52 may also bejoined to define at least two cavities, although a single cavity for theinner pouch 38 would also be within the scope of the present disclosure.As shown in FIGS. 2 and 4, the upper and lower sections 54, 56 of theinner surface 52 may be joined to form two partitions 58, 60 that inturn define three cavities, or chambers, 62, 64, 66 in which a liquidmay be disposed, as will described in greater detail below. The cavities62, 64, 66 may be of equal or unequal size; as shown, the cavity 64 islarger in volume than the cavities 62, 66.

As further illustrated in FIG. 4, the inner surface 34 of the wall 30 ofthe outer pouch 24 may be joined to itself at the first and second ends26, 28 of the outer pouch 24. In particular, as shown in FIG. 4, as wellas in FIGS. 6, 8, and 10, the inner surface 34 of the outer pouch 24 maybe joined at the second end 28 such that the second end 46 of the innerpouch 38 is disposed between the first and second sections 40, 42 of theinner surface 34 of the wall 30. In this fashion, the second end 46 ofthe inner pouch 38 may be attached to the second end 28 of the outerpouch 24. The first and second sections 40, 42 of the inner surface 34of the wall 30 may also be joined at the first end 26 to close the firstend 26 of the outer pouch 24.

In operation, the contents of the cavities 62, 64, 66 are to be releasedinto the cavity 36. Consequently, the heater product 20 may include arelease mechanism 70, which includes a pull strip 72 (which may act as abarrier, as explained in greater detail below), holes 74, 76, andpartitions 58, 60 (which may act as barriers, as explained in greaterdetail below). As will be explained in greater detail below, the releasemechanism 70 shown represents merely one possible release mechanism 70that may be used in the heater product 20 of the present invention.

The release mechanism 70 may now be discussed in greater detail withreference to FIGS. 2 and 4. In particular, the pull strip 72 may have afirst end 78 and a second end 80. In between the first end 78 and thesecond end 80 may be a first section 82, a second section 84, and athird section 86.

The first section 82 of the pull strip 72 overlies the holes 74, 76,preventing the material in cavities 62, 66 from being released into thecavity 36. The first section 82 may be releasably secured to the outersurface 50 of the inner pouch 38 through the use of, for example, apeelable seal, such as a thermally-induced peelable seal. It may not benecessary to secure the entirety of the first section 82 of the pullstrip 72 to the outer surface 50 of the inner pouch 38; for example, thefirst section 82 may be releasably secured to the outer surface 50 onlyin the area adjacent to the holes 74, 76.

The second section 84 may be connected to the first section 82, and maylie back on top of the first section 82, as best seen in FIG. 4, forexample. The second section 84 may also be disposed through an opening88 in the wall 30 of the outer pouch 24. In fact, a sealing mechanism 90may be disposed in the opening 88, and the section 84 of the pull strip72 may be disposed through the sealing mechanism 90. As best seen inFIG. 3, the sealing mechanism 90 may include an inner piece 92 and anouter piece 94, each of which may have a slit formed therethrough (onlythe slit 96 in the outer piece 94 being visible in FIG. 3) and both ofwhich may be made of, for example, a high-temperature flexible material,such as silicone rubber, polypropylene, low density polyethylene (LDPE),etc. The inner and outer pieces 92, 94 may be sealed to the wall 30 witha sealing mechanism appropriate for the materials which are used to makethe inner and outer pieces 92, 94. The section 84 of the pull strip 72may be disposed through the slits in the pieces 92, 94, which serve tokeep the heater composition within the outer pouch 24 during shipmentand to wipe the surfaces of the section 84 of the pull strip 72 as thesection 84 is removed from the heater product 20.

The third section 86 may terminate in the second end 80 of the pullstrip 72. The third section 86 of the pull strip 72 may be outside theouter pouch 24 of the heater product 20, and may include an enlargedregion 98. The enlarged region 98 may be included to make it easier forthe user of the product 20 to grip the end 80 of the pull strip 72 toapply force to the pull strip 72.

As mentioned above, the release mechanism 70 may include not only thepull strip 72 and the holes 74, 76, but also the partitions 58, 60. Inparticular, the partitions 58, 60 may include at least a weakenedsection that will permit materials to pass between the cavity 64 and thecavities 62, 66 after the weakened section has given way. For example,the partition 58 may include a middle section 100 that is weakenedrelative to side sections 102, 104, and the partition 60 may include amiddle section 110 that is weakened relative to side sections 112, 114.

The weakened sections 100, 110 may be defined in a variety of manners.As one example, seals at the weakened sections 100, 110 may not be asresistant to a pressure differential as the sections 102, 104 and 112,114. As a consequence, a significantly smaller pressure differentialexperienced across the weakened sections 100, 110 will cause thosesections to fail and give way than would cause a similar behavior insections 102, 104 and 112, 114.

As noted above, the release mechanism 70 described herein is merely oneembodiment of such a release mechanism. As one alternative embodiment,the release mechanism may include a pull strip, but rather than havingthe pull strip expose holes in the wall 48 of the inner pouch 38, thepull strip may cause the wall 48 (which acts as a barrier in thisembodiment) to separate along a section attached to the pull strip, andthereby release the contents of the inner pouch 38 into the outer pouch24. Alternatively, the release mechanism may not be an internal releasemechanism. The release mechanism may include a separate tool that may beused to puncture through the outer pouch 24 and the inner pouch 38 andrelease the contents of the inner pouch 38 into contact with thecontents of the outer pouch 24. Moreover, the tool may be provided withthe heater product 20 or heater system 22 (such as in the form of aspecially-designed tool for such purpose), or the tool may be animplement that is generally available (such as a knife or a screwdriver,for example). As a further alternative, the release mechanism mayinclude one or more seals or sealed apertures defined in the inner pouch38 in communication with the cavities 62, 66, which seals or sealedapertures (which may act as barriers) may burst under application ofsufficient pressure to the outer surface 50 of the inner pouch 38, thusremoving the barrier and releasing the contents.

As further examples, there may be variation in the release mechanism 70described above. For example, while only two holes 74, 76 are shown, theholes 74, 76 may each be replaced with a plurality of holes. Moreover, aplurality of holes may be defined in the wall 48 of the inner pouch 38,in the upper section 54 of the wall 48. These holes may be sealed untilthe time of release, and they may be of very small size. These holes maypermit the contents of the cavity 64 to be released, preferably slowly,into the contents of the outer pouch 24.

The heater product 20 and the heater system 22 may also includemechanisms that cooperate to limit the movement of the heater product 20relative to the remainder of the heater system 22 when the heaterproduct 20 is assembled with the heater system 22, although suchmechanisms are optional. Specifically, the heater product 20 may includeholes 120, 122 at the first end 26 of the outer pouch 24 and holes 124,126 at the second end 28. As best seen in FIG. 4, the heater system 22may include four anchors (two of which are shown) 130, 134 that may beattached to a base 138 and the holes 120, 122, 124, 126 to thereby limitthe movement of the heater product 20 relative to the remainder of theheater system 22. The heater product 20 may be stored separately fromthe remainder of the system 22, and may only be assembled with theremainder of the system 22, using the anchors 130, 134 for example, atthe time of activation.

As shown in the system 22 illustrated in FIG. 4, the anchors 130, 134may be shaped to be disposed about a tray 140 that may be disposed intothe base 138. In particular, the tray 140 may have an L-shaped edge 142that runs about the periphery of the tray 140 (see FIG. 3). The anchors130, 134 may each have a first (or upper) section 144 that may be shapedto be disposed about the L-shaped edge 142. The anchors 130, 134 mayalso each have a second (or lower) section 146 that may be shaped to bedisposed through one of the holes 120, 122, 124, 126. Although the lowersections 146 of, for example, the anchor 130 and the anchor 134 may havea different shape, the anchors may have the same shape as well.

Additionally, formed in the wall 30 of the outer pouch 24 is a pluralityof holes 148 used for venting. The vent holes 148 are covered with apatch 149 that is releasably attached to the outer surface 32 of thewall 30 of the outer pouch 24. The patch 149 prevents the materialsdisposed in the cavity 36 from being released through the vent holes148. As explained below, the patch 149 may be removed prior toactivation; alternatively, the patch 149 may separate from the outersurface 32 under the influence of the thermal energy, pressure, steam,etc. generated in the outer pouch 24 after activation without theinvolvement of the user (self-opening or self-releasing).

Alternatively, a valve may be used in place of or in combination withthe plurality of vent holes 148. As one such example, a valve may beused that makes an audible noise (e.g., a “whistle”) with the build upof pressure, steam, etc. in the heater product 20. The valve may thusserve as an indicator, for purposes of safety or to indicate that theproduct is “on” or “off”, for example.

Finally, as shown in FIG. 4, the heater system 22 may include a foodtray 150 and a lid 152 disposed on the food tray 150. The food tray 150may be disposed (or nestled) within the tray 140, and may have a lip 154that cooperates with the edge 142 to keep the food tray 150 disposedover the heater product 20. While there may exist a slight spacing or agap between the food tray 150 and the heater pouch 20, either initiallyor throughout the heating process, it is believed that heat transfer maybe enhanced if the food tray 150 is in contact with the heater pouch 20.

As for the contents of the outer and inner pouches 24, 38, the structureof the heater product 20 is not limited to use with a particular type ofchemical system, nor is the chemical system discussed herein limited touse in the heater product 20 described above. The heater product 20 andthe chemical system enclosed therein as disclosed below may be usefulseparate and apart from the combination discussed in greater detailherein. For example, while the heater product 20 described above hasouter and inner pouches 24, 38, each of which contains one part of atwo-part system, explained in greater detail below, inner pouch 38 maybe removed entirely, and still the two-part system discussed below maybe used, with the outer pouch 24 containing one part of the two-partsystem and the second part of the two-part system being introduced intothe outer pouch 24 by puncturing the outer pouch and pouring the secondpart into the outer pouch 24 or by being absorbed through the outerpouch 24.

Therefore, according to one embodiment of this disclosure, a two-partheater composition may be disposed in the outer and inner pouches 24,38, with the first part of the two-part heater composition initiallydisposed in the inner pouch 38 and the second part of the two-partheater composition initially disposed in the cavity 36 between the outerpouch 24 and the inner pouch 38. When the first part is released fromthe inner pouch 38, it comes in contact with the second part, and anexothermic reaction takes place.

The first part in the inner pouch 38 may include water (H₂O), and theouter pouch 24 may include a basic anhydride, such as calcium oxide(CaO) or calcium chloride (CaCl₂). The outer pouch 24 may also includean acidic anhydride, such as phosphorous pentoxide (P₂O₅), in additionto the basic anhydride. The first part in the inner pouch 38 may alsoinclude at least one chemical or composition that delays the initiationof the reaction when the water is released into contact with the calciumoxide. The first part in the inner pouch 38 may thus include sugar, suchas sucrose, glucose, or fructose, for example. The first part in theinner pouch 38 may further include at least one chemical or compositionthat limits the rate at which water is released to the calcium oxide,although this may alternatively be provided by, for example, asemi-permeable membrane that may vary its permeability according tosolubility, pressure and/or temperature. For example, this chemical orcomposition may be an absorbent, chemically-inert, thermally-resistantmaterial, such as an absorbent, mineral-based, chemically-inert,thermally-resistant material. In this regard, the first part in theinner pouch 38 may include expanded perlite (“perlite”) and/orvermiculite, for example, which material may or may not bepre-moistened. Other absorbent materials, such as charcoal and woodflour, may also be used. The first part in the inner pouch 38 may alsoinclude other chemicals or compositions that may or may be not importantto the reaction or the components of the reactive system. For example,the first part in the inner pouch 38 may include a preservative for thesugar used to delay the initiation of the exothermic reaction.

The ratio of the chemicals or compositions in the two-part systemdescribed herein may have a considerable degree of variation therein.For example, the ratio of water to calcium oxide, by weight, may varybetween 0.15:1 and 1.25:1. Moreover, while a material such as perlitemay be used, it need not be used; consequently, the ratio of perlite (ina moisture-free or bone-dry state) to water, by weight, may vary between0:1 and 0.67:1. Likewise, while a material such as sugar may be used, itneed not be used; hence, the ratio of sugar to water, by weight, mayvary between 0:1 and 0.05:1. Factors that may influence the ratios usedmay include, among others, the heater product used, the heater systemused, and the amount of material (food mass) to be warmed. It isbelieved that, relative to the amount of the material to be warmed, adirect relationship exists between the amount of material to be warmedand the amount of water and calcium oxide required; i.e., a greateramount of food mass requires more water and calcium oxide to be used.

According to one group of embodiments, useful with the heater product 20discussed above and below, the ratio of water to calcium oxide, byweight, may vary between 0.2:1 and 0.6:1, and may particularly varybetween 0.25:1 and 0.35:1. Moreover, the ratio of perlite (in amoisture-free or bone-dry state) to water, by weight, may vary between0.06:1 and 0.14:1. Further, the ratio of sugar to water, by weight, mayvary between 0.01:1 and 0.02:1. While the proportions of the chemicalsand compositions used may vary within this group, one embodimentaccording to this disclosure uses 600 g of calcium oxide, 180 g ofwater, 15 g of perlite, and 2.7 g of sugar to produce a sufficientamount of thermal energy to maintain the temperature of 2 kg of foodmass (e.g., chili) in an aluminum tray for upwards of one hour. It hasalso been found, according to another embodiment of this system, thatuse of 1200 g of calcium oxide, 360 g of water, 30 g of perlite and 5.4g of sugar produces a sufficient amount of thermal energy to maintainthe temperature of 2 kg of food mass in an aluminum tray for upwards oftwo hours. According to still another embodiment of this system, it hasbeen further found that use of 750 g of calcium oxide, 225 g of water,18.75 g of perlite and 3.375 g of sugar produces a sufficient amount ofthermal energy to maintain the temperature of 2 kg of food mass in analuminum tray for upwards of two hours. This further embodiment alsoincluded certain preservatives (0.4 g of citric acid (anhydrous) 99%,0.2 g of sodium benzoate 99%, and 0.2 g of potassium sorbate 99%).

Other embodiments of the composition are possible.

For example, it has been found that suitable amounts of heat (forexample, to maintain the temperature of 2 kg of food mass forapproximately 45-50 minutes) may be produced when 200 g of calcium oxideis combined with a liquid component that includes 100 g of water and 1.5g of sugar, the ratio of water to calcium oxide being 0.5:1 and theratio of sugar to water being 0.015:1. Similar compositions using thesame ratio of calcium oxide, water and sugar have also been tested andfound useful, such as 400 g calcium oxide, 200 g water, and 3 g sugar;420 g calcium oxide, 210 g water, and 3.15 g sugar; 450 g calcium oxide,225 g water, and 3.38 g sugar; 500 g calcium oxide, 250 g water, and3.75 g sugar; and 800 g calcium oxide, 400 g water, and 6 g sugar.

Additionally, it has been found that suitable amounts of heat (forexample, to maintain the temperature of 2 kg of food mass forapproximately one hour) may be produced when 500 g of calcium oxide iscombined with a liquid component that includes 125 g of water and 1.56 gof sugar, the ratio of water to calcium oxide being 0.25:1 and the ratioof sugar to water being 0.012:1. It has also been found that suitableamounts of heat may be produced when 600 g of calcium oxide is combinedwith a liquid component that includes 150 g of water and 2.25 g ofsugar, the ratio of water to calcium oxide being 0.25:1 and the ratio ofsugar to water being 0.015:1.

It has further been found that suitable amounts of heat (for example, tomaintain the temperature of 2 kg of food mass for approximately 90minutes) may be produced when 600 g of calcium oxide is combined with aliquid component that includes 180 g of water, 2.7 g of sugar and 15 gof perlite, the ratio of water to calcium oxide being 0.3:1, the ratioof sugar to water being 0.015:1, and the ratio of perlite to water being0.08. Similar success was found with similar amounts of calcium oxide,water and sugar and varying amounts of perlite, including 17.5 g(0.10:1), 20 g (0.11:1), 25 g (0.14:1) and 30 g (0.17:1). Suitableamounts of heat were also produced when 1200 g of calcium oxide iscombined with a liquid component that includes 360 g of water, 5.4 g ofsugar and 40 g of perlite, the ratio of water to calcium oxide being0.3:1, the ratio of sugar to water being 0.015:1, and the ratio ofperlite to water being 0.11:1.

It has also been found that suitable amounts of heat (for example, tomaintain the temperature of 2 kg of food mass for approximately 90minutes) may be produced when 600 g of calcium oxide is combined with aliquid component that includes 180 g of water, 9 g of sugar and 20 g ofperlite, the ratio of water to calcium oxide being 0.3:1, the ratio ofsugar to water being 0.050:1, and the ratio of perlite to water being0.11:1.

To assemble the heater product 20, the inner pouch 38 may be initiallyformed with ends 44, 46 closed and the pull strip 72 disposed over theholes 74, 76, but with at least one side seam 158 open. A mixture ofwater, perlite and sugar may be disposed into each of the three cavities62, 64, 66. According to one embodiment, the cavities 62, 64, 66 arefilled with unequal proportions of the mixture; for example, theproportions for the cavities 62, 64, 66 may be 20:60:20. The side seam158 may then be sealed. The second and third sections 84, 86 of the pullstrip 72 may then be disposed through the sealing mechanism 90, whichmay already be fitted in the opening 88 of the wall 30 of the outerpouch 24. The cavity 36 may then be filled with calcium oxide. The end28 of the outer pouch 24 may then be sealed with the end 46 of the innerpouch 38 inside the seal, thereby attaching the inner pouch 38 to theouter pouch 24.

It may be noted that, as shown, the orientation of the inner pouch 38relative to the outer pouch 24 places the holes 74, 76 facing upwards.It is believed that this orientation of the holes 74, 76 may limitpooling of the material in the inner pouch 38 beneath the inner pouch 38after release. Additionally, as shown, the inner pouch 38 is positionedsuch that it is proximate to the bottom of the outer pouch 24. It isbelieved that this orientation of the inner pouch 38 relative to theouter pouch 24 prevents the inner pouch and/or the contents of the innerpouch 38 from acting as an insulator, limiting exchange of thermalenergy with the food tray 150. Moreover, the release mechanism 70 isdisposed on top of the inner pouch 38 as shown. It is believe that thisorientation of the release mechanism 70 may limit the resistance thatthe calcium oxide may present relative to removal of the releasemechanism 70 from the heater product 20.

To assemble the heater product 20 with the remainder of the heatersystem 22, the anchors 130 may be disposed through the holes 120, 122 inthe first end 26 of the outer pouch 24, with the anchors 130 alreadyattached to the tray 140 and the product 20 oriented as shown in FIG. 4with the opening 88 in the wall 30 of the outer pouch 24 disposed facingthe bottom of the tray 140. The anchors 134 may then be disposed throughthe holes 124, 126 in the second end 28 of the pouch 24. The food tray150 may then be disposed so that the lip 154 of the food tray 150 abutsand rests on the edge 142 of the tray 140.

To activate the heater product 20, the user may first remove the patch149 from over the vent holes 148. The user may then grasp the enlargedregion 98 of the pull strip 72, and may apply an outward force to thepull strip 72 until at least the holes 74, 76 have been exposed.According to one embodiment of the disclosure, force may be applied tothe pull strip 72 until the entire pull strip 72 has been removed fromthe heater product 20.

As the water/perlite/sugar mixture is released into the calcium oxide,the exothermic reaction may be initially delayed by the presence of thesugar, to permit, for example, the user to assemble the heater product20 with the remainder of the heater system 22 (e.g., by disposing theheater product 20 into the tray 140 and disposing the tray 150 on top ofthe tray 140 and the heater product 20). After the initial release ofwater into contact with the calcium oxide, further release of water tothe calcium oxide may occur in a controlled fashion by virtue of, forexample, the presence of the perlite and the multiple cavities orchambers 62, 64, 66 of the inner pouch 38. That is, it is believed that,as the perlite material is heated, the perlite material may releasemoisture in the form of steam into contact with the calcium oxide in theouter pouch 24. Additionally, the thermal energy generated by therelease of moisture in contact with the calcium oxide, may cause thewater/perlite/sugar mixture in the second cavity 64, which has remainedsealed thus far, to increase in temperature. It is presently believedthat, as the temperature of the mixture increases, given that the amountof mixture present is constant and the volume of the cavity 64 isrelatively constant, the pressure in the cavity 64 increases and causesa pressure differential across the weakened sections 100, 110. It isalso believed that an increase in pressure in the cavity 64 may also becaused by the interaction between the trays 140, 150 and the heaterproduct 20. Further, it is believed that the seals that form thepartitions 58, 60 may begin to weaken because of the increase intemperature. Eventually, the weakened section 100, 110 of at least oneof the partitions 58, 60 may fail and give way, causing the material inthe second cavity 64 to be released, preferably slowly, into contactwith the calcium oxide in the cavity 36 via at least one of the cavities62, 66. As an alternate path, the material in the second cavity 64 mayalso be released via the plurality of small holes defined in the uppersection 54 of the wall 48, as discussed above.

It is believed that by using a system in which water and water vapor arereleased in a controlled fashion into contact with the calcium oxide,undesirable spiking of the temperature of the food may be avoided. Thatis, it is believed that the gradual release of the water to the calciumoxide, through the use of moisture-absorbent material, for exampleperlite, and the sequential release of the first part of the two-partsystem from the cavities 62, 64, 66 may cause undesirable spiking of thetemperature of the food to be avoided, which may have the additionalconsequence of avoiding charring of the food. It is also believed thatthe gradual release of thermal energy may improve the efficiency of theexchange of thermal energy between the heater product 20 and the foodtray 150. Further, it may improve the overall efficiency of the system22 by minimizing the energy losses to the production of vented steam.

The reaction between the water and the calcium oxide continues for someamount of time, during which time thermal energy may be supplied to thefood in the food tray 150. The thermal energy may be supplied to thefood in the tray 150 along a first path defined by contact between theheater pouch 20 and the food tray 150. However, thermal energy may alsobe supplied to the food in the food tray 150 as a consequence of therelease of, for example, steam from the heater product 20, even if theheater product 20 is not in direct contact with the food tray 150.Because the indirect exchange of thermal energy through steam may not beas efficient as the direct exchange of thermal energy through contact,it may be preferred to partially close the vent holes 148 throughcontact with the underside of the food tray 150 to prevent steam losses.

Having thus discussed the structure, assembly and operation of anembodiment of the heater product 20 and heater system 22, the furtherembodiments of the present disclosure are discussed.

FIGS. 4-15 show various alternative embodiments of the heater system 22using a heater product 20, as previously described. In discussing theseadditional embodiments, similar elements will be designated usingsimilar reference numerals with the use of a single prime for theembodiment shown in FIGS. 5 and 6, a double prime for the embodimentshown in FIGS. 11 and 12, and a triple prime for the embodiment shown inFIGS. 13 and 14. While the heater product 20 is common to all fourembodiments of the heater system 22, this need not necessarily be thecase, and the structure of the heater product 20 and the composition ofthe materials disposed in the heater product 20 may vary between andamong the various embodiments.

While the embodiment shown in FIG. 4 has a base 138 into which aplurality of trays 140, 150 are nested, with the heater product 20disposed between the trays 140, 150, the embodiment of the heater system22′ shown in FIGS. 5 and 6 includes a different mechanism for disposingthe heater product 20′ proximate to the food tray 150′. As shown, thebase 138′ has an opening 170 formed in the side, as well as an openingin the top through which the food tray 150′ is disposed. Into theopening 170 is disposed a drawer 172, which can be moved relative to thebase 138′ between an open state, as shown in FIG. 5, and a closed state,as shown in FIG. 6. The drawer 170 has side walls 174 and a bottom 176,which define a receptacle 178 into which a heater product 20′ may beplaced. Rather than using the clip-like anchors 130, 134 shown in FIG.4, anchors 180 (two of which are shown in FIG. 6) are used that areattached to the side walls 174. The anchors 180 cooperate with the holes120, 122, 124, 126 as the anchors 130, 134 did in the previousembodiment.

The embodiment of FIGS. 7-10 is similar to that shown in FIGS. 5 and 6in that a drawer is included in the base, and is moveable between anopen state and a closed state. The embodiment of FIGS. 7-10 differs fromthat shown in FIGS. 5 and 6 in that a lid is included above the base,covering the food tray to prevent loss of heat.

The embodiment of FIGS. 11 and 12 shows a heater system 22″ wherein theheater product 20″ is used with a conventional chafer dish arrangement.In this embodiment, anchors 130″, 134″ (two of which are shown) similarto those used in FIG. 4 are included to limit the movement of the heaterproduct 20″ relative to the remainder of the system 22″. Further, a thinplatform, or spacer, 190 may be disposed under the heater product 20″ toensure the proximity between the heater product 20″ and the food tray150″.

The embodiment of FIGS. 13 and 14 shows a heater system 22′″, in theform of a take-out container, wherein the heater product 20′″ is usedwith a nested arrangement of trays, as is shown in FIG. 4. However,unlike the nested arrangement of trays shown in FIG. 4, anchors 200 areattached, as in the embodiment shown in FIGS. 5 and 6, to the side walls202 of the tray 140′″ that is disposed into the base 138′″. For thatmatter, the trays need not be nested, but instead stacked one on top ofthe other to form a space in between into which a heater product 20′″may be disposed.

Also illustrated, in FIG. 15, is an alternative embodiment of the heaterproduct 20, which will be designated with the reference numeral 20A.Unlike the heater product 20, the heater product 20A may include anouter tray 210 and an inner pouch 212. The outer tray 210 may have anopening 214 over which a lid 216 may be disposed. The outer tray 210 mayhave a lip 218 that extends about the periphery of the tray 210 andabout which an edge 220 of the lid 216 may be secured, by crimping, forexample. In particular, the inner pouch 212 may have a tail section 222that is secured to the outer tray 210, by securing the tail section 222between the tray 210 and the lid 216. The heater product 20A may alsoinclude a release mechanism 224, which may be of the pull-strip varietythat causes a wall of the inner pouch 212 to separate to permitmaterials within the inner pouch 212 to be released into the outer tray210.

In assembly, the inner pouch 212 may be filled with the first part(e.g., water/sugar/perlite) of the two-part exothermic compositionreferenced above, although other compositions and system may be used.The inner pouch 212 may then be disposed in the outer tray 210, with thetail section 222 disposed on the lip 218 of the tray 210. The outer tray210 may then be filled with other part (e.g., calcium oxide and/orphosphorous pentoxide) of the two-part system. The lid 216 may then bedisposed onto the outer tray 210, with the release mechanism (pullstrip) 224 fed through an opening 226 in the lid 216. The edge 220 ofthe lid 216 may then be crimped about the lip 218 of the tray 210,thereby closing the tray 210 and securing the pouch 212 to the tray 210.

In operation, an end of the release mechanism 224 may be grasped by theuser, and a force applied to separate or tear the wall of the innerpouch 212 along a line of attachment of the release mechanism 224 withan outer surface 228 of the inner pouch 212. The tearing or separationof the inner pouch 212 may cause the contents of the inner pouch 212 tobe released into the material in the outer tray 210.

It may be noted that because the outer tray 210 may be made of a morerigid material than the outer pouch 24 of the heater product 20, it maynot be necessarily to utilize a system of anchors, as shown in theembodiments of the system 22, 22′, 22″, 22′″. Moreover, the rigidity ofthe product 20A may also assist in maintaining a consistent area ofcontact between the product 20A and a food tray disposed on top of theproduct 20A, for example.

Additionally illustrated, in FIGS. 16 and 17, is an alternativeembodiment of the inner pouch 38 of the heater product 20, thealternative embodiment being designated with the reference numeral 38A.The inner pouch 38A may be assembled with the other components of theheater product as shown in FIGS. 1 and 2 relative to inner pouch 38, andas explained in greater detail below.

Unlike the inner pouch 38, the inner pouch 38A may have a single cavity250 that may be formed by sealing (e.g., heat sealing) the inner pouch38A along ends 252, 254 and 256, 258. Also unlike the inner pouch 38,the inner pouch 38A has no holes 74, 76, but instead relies upon ruptureof the inner pouch wall 260 to release the contents therefrom.

In particular, a pull tab, or strip, 262 may be fixedly secured (e.g.,with one or more heat seals) to an outer surface 264 of the inner pouchwall 260, which pull tab 262 may depend from the heater product in thesame or similar fashion to the pull tab 72 illustrated in FIGS. 1 and 2.Strips 266, 268 of reinforcing material (such as, for example,SCOTCH-brand Reinforced Filament Tape #8981, available from 3M of St.Paul, Minn.) may also be fixedly secured to the outer surface 264 of theinner pouch wall 262. The first strip of reinforcing material 266 may bedisposed such that it is axially aligned with the pull tab 262, whilethe strips 268 may be disposed at an angle to a line that passes throughthe pull tab 262 and the first strip 266.

In use, force may be applied to the pull tab 262 causing it to move fromthe left to the right, across the inner pouch 38A as shown in FIGS. 16and 17. This, in turn, may cause the inner pouch wall 260 to rupture.The first strip 266 of reinforcing material, which may be partiallyoverlapped by the pull tab 262, may guide the tear in the inner pouchwall 260 initiated by the force applied to the pull tab 262 so as tolimit the likelihood that the tear will be too small to release thecontents of the inner pouch 38A. On the other hand, the strips 268 mayguide the tear in the inner pouch wall 260 to limit the likelihood thatthe tear will be too large such that the user will be unable to removethe pull tab 262 and associated portion of the ruptured inner pouch wall260 from the heater product.

FIGS. 18-23 illustrates an alternative heater product 20B, with an outerpouch 300 similar to that shown in FIGS. 1 and 2 and an inner pouch 314similar to that shown in FIGS. 16 and 17.

As shown in FIG. 18, the heater product 20B may include an outer pouch300 (made of, for example, foil on a linear low density polyethylenesealant) having a first end 302 and a second end 304. As shown in FIG.19, the outer pouch 300 may include a pouch wall 306, which may beflexible, semi-rigid, rigid, etc., having an outer surface 308 and aninner surface 310 (see FIG. 20C). The inner surface 310 of the pouchwall 306 may define a cavity 312 in which is disposed an inner pouch314. The inner surface 310 of the pouch wall 306 may be described ashaving a first section and a second section, which with the pouch 300disposed as illustrated in FIGS. 18 and 19 may be described as an uppersection and a lower section.

The inner pouch 314 (made of, for example, polyester on foil on apolyethylene sealant) also has a first end 320 and a second end 322. Asshown in the Figures, the inner pouch 314 also includes a pouch wall 324having an outer surface 326 (FIG. 18) and an inner surface 328 (FIG.21). Moreover, the inner surface 328 of the pouch wall 324 may bedescribed as having a first (or upper) section and a second (or lower)section.

It should be noted that designations such as “upper” and “lower” are forease of discussion only, and are not meant to limit the disclosure inany fashion, for a similar designation may be used if the pouch wasinverted with the second section of the outer pouch being “upper” andthe first section being “lower” and the second section of the innerpouch being “upper” and the first section being “lower.”

As illustrated in FIG. 21, the wall 324 of the inner pouch 314 may besealed at both the first and second ends 320, 322. Thus, similar to theembodiment of the inner pouch 38A shown in FIGS. 16 and 17, the innerpouch 314 has a single cavity 334. Unlike the embodiment of inner pouch38A, the seals at the first and second ends 320, 322 may have achevron-shaped section, which chevron-shaped section may assist inlowering the pull force required to tear the wall 324 of the inner pouch314.

As further illustrated in FIG. 19, the inner surface 310 of the wall 306of the outer pouch 300 may be joined to itself at the first and secondends 302, 304 of the outer pouch 300. In particular, as shown in FIG.19, the inner surface 310 of the outer pouch 300 may be joined at thesecond end 304 such that the second end 322 of the inner pouch 314 isdisposed between the first and second sections of the inner surface 310of the wall 306. In this fashion, the second end 322 of the inner pouch314 may be attached to the second end 304 of the outer pouch 300. Thefirst and second sections of the inner surface 310 of the wall 306 mayalso be joined at the first end 302 to close the first end 302 of theouter pouch 300.

The outer and inner pouches 300, 314 may also be attached together inother ways. For example, the outer surface 326 of the inner pouch 314may have adhesive strips 339 attached thereto, as shown in FIG. 23. Theadhesive strips may be used to attach the outer an inner pouches 300,314 together to limit the space beneath the inner pouch 314 between theouter pouch 300 and the inner pouch 314.

In operation, the contents of the cavity 334 are to be released into thecavity 312. Consequently, the heater product 20B may include a releasemechanism 340, which includes a pull strip 342 and strips of reinforcingmaterial 344, 346. In this regard, the inner pouch 314 is similar to theinner pouch 38A shown in FIGS. 16 and 17.

The release mechanism may now be discussed in greater detail withreference to FIGS. 19 and 22. In particular, the pull strip 342 (madeof, for example, nylon laminated to a low density polyethylene sealant)may have a first end 348 and a second end 350. In between the first end348 and the second end 350 may be a first section 352, a second section354, and a third section 356.

The first section 352 of the pull strip 342 may be fixedly secured(e.g., with one or more heat seals) to the outer surface 326 of theinner pouch wall 324. The strips 344, 346 of reinforcing material (suchas, for example, SCOTCH-brand Reinforced Filament Tape #8981, availablefrom 3M of St. Paul, Minn.) may also be fixedly secured to the outersurface 326 of the inner pouch wall 324. The first strip of reinforcingmaterial 344 may be disposed such that it is axially aligned with thepull strip 342, while the strips 346 may be disposed parallel to andslightly offset from a line that passes through the pull strip 342 andthe first strip 344. There also exists a gap between the first strip 344and the second strips 346.

In use, force may be applied to the pull strip 342. This, in turn, maycause the inner pouch wall 324 to rupture. The first strip 344 ofreinforcing material, which may be totally overlapped by the pull strip342 (see FIG. 19, only a portion of the pull strip 342 is shown in FIG.22 to improve clarity), may guide the tear in the inner pouch wall 324initiated by the force applied to the pull tab 342 so as to limit thelikelihood that the tear will be too small to release the contents ofthe inner pouch 314. On the other hand, the strips 346 may guide thetear in the inner pouch wall 324 to limit the likelihood that the tearwill be too large such that the user will be unable to remove the pullstrip 342 and associated portion of the ruptured inner pouch wall 324from the heater product.

The second section 354 may be connected to the first section 352, andmay lie back on top of the first section 352, as best seen in FIG. 19,for example. The second section 354 may also be disposed through anopening 360 in the wall 306 of the outer pouch 300. In fact, a sealingmechanism 362 (see FIGS. 20A-20C) may be disposed beneath the opening360, and the section 354 of the pull strip 342 may be disposed throughthe sealing mechanism 362 and then the opening 360.

As best seen in FIG. 20A, the sealing mechanism 362 may include a firstpiece 364, a second piece 366 and a third piece 368, although themechanism may be formed as a one or two-piece mechanism as well. Thefirst piece 364 and the second piece 368 may have slits 370, 372 formedtherethrough, while the middle piece 364 may have a larger slot 374formed therethrough. All three pieces 364, 366, 368 may be made of, forexample, low density polyethylene (LDPE). The three pieces 362, 364, 368may be joined together, for example through the use of fasteners, suchas staples, as shown in FIG. 20B. As shown in FIG. 20C, the assembly ofpieces 362, 364, 366 may then be attached to the inner surface 310 ofthe wall 306 through the use of an attachment patch 376, as shown, theattachment patch 376 also having a slit (not shown) formed therethrough.In operation, the cavity defined by the slot 374 may act as a “catch” toreceive any material that is not removed from the strip 342 by the thirdpiece 368, but that is removed by the first piece 362.

The third section 356 may terminate in the second end 350 of the pullstrip 342. The third section 356 of the pull strip 342 may be outsidethe outer pouch 300 of the heater product 20B, and may include anenlarged region 380. The enlarged region 380 may be included to make iteasier for the user of the product 20B to grip the end 350 of the pullstrip 342 to apply force to the pull strip 342.

The embodiment of heater product 20B may also differ from that shown inFIGS. 1 and 2 in that the vent holes 148 have been replaced with anumber of pinholes 390 (see FIG. 18). In fact, the several hundredpinholes may be made in the wall 306 of the outer pouch 300. Thesepinholes 390 may permit steam to escape from the outer pouch 300 duringoperation. While the holes 390 should be small enough to prevent theescape of materials from the outer pouch 300, the holes 390 (and theopening 360) may be covered by a removable adhesive label that preventsloss of material in shipment and may be removed prior to activation.

1. A heater product comprising: a first cavity in which a first part ofa heater composition is disposed, the first part comprising calciumoxide; a second cavity in which a second part of a heater composition isdisposed, the second part comprising water, an reaction-initiationdelayer and water-release limiter; and a barrier between the firstcavity and the second cavity, such that when the barrier is removed, thefirst and second parts combine to provide an exothermic reaction.
 2. Theheater product according to claim 1, wherein the reaction-initiationdelayer comprises sugar.
 3. The heater product according to claim 2,wherein the sugar comprises sucrose, glucose or fructose.
 4. The heaterproduct according to claim 1, wherein the water-release limitercomprises an absorbent, chemically-inert, thermally-resistant material.5. The heater product according to claim 4, wherein the water-releaselimiter comprises perlite.
 6. The heater product according to claim 5,wherein the reaction-initiation delayer comprises sugar.
 7. The heaterproduct according to claim 6, wherein the ratio of water to calciumoxide, by weight, may vary between 0.15:1 and 1.25:1, the ratio of sugarto water, by weight, may vary between 0:1 and 0.05:1, and the ratio ofthe perlite to water, by weight, may vary between 0:1 to 0.67:1.
 8. Theheater product according to claim 7, wherein the ratio of water tocalcium oxide, by weight, may vary between 0.2:1 and 0.6:1, the ratio ofsugar to water, by weight, may vary between 0.01:1 and 0.02:1, and theratio of the perlite to water, by weight, may vary between 0.06:1 to0:0.14.
 9. The heater product according to claim 8, wherein the ratio ofwater to calcium oxide, by weight, may vary between 0.25:1 and 0.35:1,the ratio of sugar to water, by weight, may vary between 0.01:1 and0.02:1, and the ratio of the perlite to water, by weight, may varybetween 0.06:1 to 0:0.14.
 10. The heater product according to claim 8,wherein the ratio of water to calcium oxide, by weight, is 0.3:1, theratio of sugar to water, by weight, is 0.015:1, and the ratio of theperlite to water, by weight, is 0.083:1.
 11. The heater productaccording to claim 10, further comprising preservatives.
 12. A heaterproduct comprising: an outer pouch, the outer pouch having a wall withan inner surface that defines an outer pouch cavity and an openingtherethrough; an inner pouch disposed within the outer pouch cavity andattached to the outer pouch, the inner pouch having a wall with an innersurface that defines at least one inner pouch cavity and an outersurface; a pull strip with a first portion secured to the outer surfaceof the inner pouch and a second portion disposed through the opening inthe outer pouch; at least one reinforcing strip secured to the outersurface of the inner pouch to guide a tear formed in the wall of theinner pouch when force is applied to the pull strip; a first part of aheater composition disposed in the outer pouch cavity and a second partof a heater composition disposed in the inner pouch cavity, the firstand second parts capable of an exothermic reaction when combined. 13.The heater product according to claim 12, further comprising first andsecond reinforcing strips, the first and second reinforcing stripssecured on either side of the pull strip.
 14. The heater productaccording to claim 13, wherein the first and second reinforcing stripsare parallel to the pull strip substantially along the first portion.15. The heater product according to claim 12, wherein the first portionof the pull strip is aligned with and overlaps the at least onereinforcing strip.
 16. The heater product according to claim 12, whereinthe at least one reinforcing strip comprises at least one strip ofreinforced tape applied to the outer surface of the inner pouch.
 17. Theheater product according to claim 12, wherein the first part comprisescalcium oxide and the second part comprises water.
 18. The heaterproduct according to claim 17, wherein the second part comprises areaction-initiation delayer and a water-release limiter.
 19. The heaterproduct according to claim 18, wherein the reaction-initiation delayercomprises sugar and the water-release limiter comprises perlite.
 20. Theheater product according to claim 12, further comprising a sealingmechanism disposed proximate to the opening, the sealing mechanismincluding first and second pieces each with a slit formed therethroughand the second portion of the pull strip disposed through the slits inthe first and second pieces.
 21. The heater product according to claim20, wherein the sealing mechanism includes a third piece disposedbetween the first and second pieces, the third piece having a slotformed therethrough that is larger than the slits formed in the firstand second pieces, the slot defining a cavity to receive materialremoved from the pull strip.